This project will examine multiple androgen dependent and independent biochemical variables of the rat ventral prostate in order to evaluate the consequence of senescence-associated reductions in the prostatic complement of androgen receptors upon the capability of senescent prostatic cells to regulate the expression of genetic information. The experiment will also evaluate the possible causal relationship between plasma androgen levels and prostatic androgen receptor content. The protocols will provide for the correlation of quantitative morphometric measurements of prostatic ultrastructural features and specfic androgen dependent prostatic enzyme activities; which will include 5 alpha-reductase, acid phosphatase, aldolase, and the enzymes of polyamine biosynthesis, with determinations of total androgen receptor content. The androgen dependent and independent processes will be measured both as early inductive and late chronic trophic responses in young mature (90-120 day old), aging (18 month old) and senescent (30 month old) inbred rats. The data will be analyzed for the interaction of age, and androgen receptor content with the androgen medicated expression of prostatic genetic information.